Magnetic catch



R. E. FOLTZ 3,186,748

MAGNETIC CATCH June 1, 1965 Filed Oct. 31, 1962 VEN OR.

ZZZ W United States Patent 0."

3,186,748 MAGNETIC CATCH Robert E. Foltz, Sterling, 'llL, assignor to Lawrence Brothers, Inc, Steriing, Iil., a corporation of Illinois Filed Oct. 31, 1962, Ser. No. 234,421 2 Claims. (Cl. 292-2515) This invention relates generally to catches for cabinet doors and for analogous closures. The invention relates more particularly to magnetic catches for such structures.

In the past, numerous types of magnetic catches have been devised for use in securing a door to which a magnetically permeable strike plate was attached; and a rather universal design objective for these catches has been the accommodation of minor misalignments of the catch and the strike plate. When a magnetic catch has achieved this objective, approximate closing of the door is intended to complete a magnetic circuit of sufficient strength to finish the closing action and insure retention of the door in place. Precise mounting of such a catch to the cooperating door frame member is no'longer critical to succes'sful functioning of the catch, the requisite installation time and skill being thereby reduced substantially.

However, minor misalignments of the catch and strike plate have heretofore been reconciled by allowing the component magnet a certain freedom of movement within the catch housing; and when a magnet assembly comprising a bar magnet and pole pieces has been employed, the pole pieces have been commonly granted appreciable freedom of movement by being only magnetically and not mechanically attached to the magnet. While this latter arrangement permits substantial accommodation of the relative positioning of the catch and strike plate, it has been found that thetotal magentic force available from the magnet is not realized until the strike plate has been situated in full contact with both pole pieces by t e closing action of the door. Thus, while actual positioning of the catch on the door frame member is not critical, a careful manipulation of the door is important to obtain the full closing effect. Most householders are not in the habit of exercising this degree of care when closing cabinet doors.

Therefore, an important object of the present invention is to provide a magnetic catch incorporating pole pieces which are positively and mechanically coupled to the associated magnet for movement in unison into full magnetic contact with a cooperating strike plate.

A more general object of the invention is to provide a new and improved magnetic catch. 7

Another object of the invention is to provide a magnetic catch which is arranged to realize the full magnetic capabilities of its component magnet.

Still another object of the invention is to provide a magnetic catch having a comparatively quiet latching action.

And still another object of the invention is to provide a magnetic catch which achieves a highly positive uniting of its component pole pieces and magnet.

Yet another object of the invention is to provide a magnetic catch that takes full advantage of the properties of its component magnet and pole pieces in uniting the same into a permanently aligned assembly.

These and other objects and features of the invention will become more apparent from a consideration of the following descriptions.

A catch structure in accord with the invention includes a non-magnetic housing defining a chamber with an opening generally confronting a door that is provided with a strike plate, and a magnet assembly mounted in the chamber for rotation through a small angle therein whereby to accommodate the relative positioning of the catch i atented June 1, 1965 and the strike plate, the magnet assembly including a permanent magnet, a magnetically permeable pole piece disposed in contact with each of the pole faces of the magnet, and aggressively interengaging apertures and protrusions acting between the magnet and the pole pieces positively and mechanically to couple the pole pieces for rotation in unison into full magnetic contact with the strike plate. 1

In order that the principle of the invention may be readily understood, a single embodiment thereof, but to which the application is not to be restricted, is shown in the accompanying drawing wherein:

FIG. 1 is a perspective view of a magnetic catch constructed in accordance with the invention and shown mounted on a door frame member for securing a door that is provided with a magnetically permeable strike plate;

FIG. 2 is an enlarged, top plan View of the catch installation of FIG. 1, the angle of rotation of the magnet assembly being shown by a solid line and a broken line illustration of the magnet assembly;

FIG. 3 is an exploded perspective viewof the magnet assembly and a cooperating support plate;

FIG. 4 is a reduced scale view taken substantially along the line 44 of FIG. 2; and

FIG. 5 is an enlarged view taken substantially along the line 55 of FIG. 1.

Referring now in detail to the drawing, specifically to FIGS. 1 and 2, a magnetic catch indicated generally by the numeral 10 will be seen mounted to a door frame member 12 in position to secure a door 14- which is provided with a magnetically permeable strike plate 1o. As is best shown in FIG. 2, the strike plate 16 is fashioned with a central, conical bore 18 for receiving the head of a fiat-headed screw 20 in flush relationship, screw 20 fastening the strike plate 15 to the door 14. Advantageously, a pair of spaced lugs 22 are extruded from the strike plate to be urged piercingly into the face of door 14 upon tightening of the screw 20. The lugs 22, thus, serve to position the strike plate in non-rotatable relationship relative to the door 14.

The magnetic catch 19 comprises a housing 24 and a magnet assembly 26. The housing 24 is fabricated from a non-magnetic material such as sheet aluminum and is arranged to include a top plate member 28 and side plate members 313 as is best shown in FIG. 4. The plate members 28 and 30 cooperate to define a chamber opening generally toward the door 14 as is well shown in FIG. 5. In addition, the side plate members 30 terminate at their lower edges in mounting flanges 32, flanges '32 being slots 44 that are cut in the side plate members 3!) adf.

jacent their juncture with the flanges 32.

In order that the magnet assembly 26 may rotate through a small angle within the chamber defined in housing 24, the relative sizes of the housing and magnet assembly are selected to space the sides of the magnet assembly from the opposite side plate members 30 of the housing as is indicated in FIG. 4. This small angle of rotation which is permitted the magnet assembly is indicated in FIG. 2 by a broken line and a solid line showing of the magnet assembly. The permissive rotation allows the magnet assembly to move and accommodate the relative positioning of the catch 10 and the strike ta plate 16.. A certain amount of latitude in installing the catch on the door frame member 12 is thus achievedJ together with a rubber composition as by being molded therein. A central bore 52 and coupling apertures 54 are provided in the permanent magnet 46, the bore 52 passing through the magnet and the apertures 54 opening from the opposite pole faces as by comprising bores perforating the body of the magnet. 4

The pole pieces 48 and 50 are advantageously fabricated from a suitable magnetic material such as mild steel; and the pole pieces are perforated with central bores 56 which are alignable with the bore 52 in magnet 46 and with the bore 40 in plate 38. With the several bores thus aligned, a stud 'or rivet 58 canbe passed through a hole in the top plate member vof the housing to freely enter the aligned bores 40, 52 and 56 as is Well shown in FIGS. 4 and 5. The stud 58 is provided with a head 60 and a riveted-over foot 62 by which the stud is fixed to the housing 24. 50 disposed, the stud 58 defines a pivot for the magnet assembly 26. V Returning to FIG. 3, the pole pieces 48 and 50 are seen fashioned with bosses or protrusions64 which are situated at eccentric locations to engage the coupling apertures 54 of the bar magnet in an interference fit. Thus, the pole pieces are positively and mechanically coupled together for rotation in unison about the stud 58 and into full magnetic contact with the strike plate; The protrusions comprise detents which are extruded from the pole pieces to take adiameter' larger'than the diameter of the coupling apertures 54; and therefore, the oversized detents resiliently deform the walls of the cou- Moreover, the full magnetic force available from the magnet 46 is. at play as the strike plate approaches the magnetic catch. This situation tends to achieve a preliminary alignment of the magnet. assembly before actual contact is made with the strike plate. Thus, only small movementsof the magnet assembly are required to bring it into full contact with the strike plate. An almost imperceptible click on contact of the parts results. In addition, only a single click is caused because the two pole pieces move in unison. Accordingly, the magnetic catch of the invention achieves a comparatively quiet closing action.

The specific example herein shown and described is to be considered as being primarily illustrative. Various changes in struoturewill, no doubt, occur to those skilled in the art; and such changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

' 1. A magnetic catch adapted to secure a door that is provided with a magnetically permeable strike plate, said catch comprising: a housing of non-magneticmaterial including side and top platememberscooperating to de: fine a chamber with anopening generally confronting said door; a magnet assembly mounted in said chamber and spaced from opposite side plate members of said housing for rotation through a small angle therein whereby to accommodate the relative positioning of said catch and said strike plate, said magnet assembly inpling apertures 54 to insure positive coupling of the pole pieces to the magnet and to each other. In addition, as is shown in FIGS. 2 and 5, the pole pieces 48 and 50 are situated to extend respective edgeportions from the front opening in the housing 24 in order to engage the strike plate 16 in a ready and facile manner.

From the descriptions thus far given, it is apparent that, as the strike plate 16 approaches the magnet assembly, a point will eventually be reached at which a v certain amount of magnetic flux will pass through the strike plate; and in response, the magnet assembly will shift or rotate within the housing to become aligned withthe approaching strike plate. strike plate actually contacts the confronting edges of the pole pieces, the magnet assembly will be approxi-, mately aligned with the strike plate;,and any slight misalignments will be immediately corrected by the magnetic force of the magnet 46. Since the pole pieces 48 and 50 are positively and mechanically coupled together, the magnetic circuit passes through the strike plate and through both pole pieces, bringing the full magnetic capability of the magnet 46 into play for properly aligning the magnet assembly with the strike plate. There is no possibility, therefore, that only one of the pole pieces will be drawn into full engagement with the strike plate. The catch of the invention is thus capable of completing the closing action of the door and insuring its retention in place. Y

At the moment the eluding a permanent magnet comprising magnetic par ticles bonded together by a rubber matrix, said magnet having coupling apertures opening from opposite pole faces thereof, said assembly further including a magnetically permeable metal pole piece disposed in contact with each of said faces' and extending :an edge portion through the opening in said chamber whereby readily to engage said strike plate, said pole pieces having integral boss means disposed inwardly from the margins thereof and pressed into said coupling apertures with a press fit therebetween, said .pole pieces being positively and mechanically coupled to said magnet substantially immovably locking said edge pontions in alignment for rotation in unison into full magnetic contact with said strike plate; and stud means penetrating said top plate member and said magnet assembly to retain said assembly in said chamber and provide a pivot about which said assembly, is rotatable.

2. A magnetic catch according to claim 1 wherein said boss means include detents extruded from each of said pole pieces at eccentric locations References Cited by the Examiner UNITED STATES' PATENTS 2,627,097 2/53 Ellis- 2,837,366 6/58 4 L66 292. 2s1-.5 2,862,752 12 58 Heppner 292 251.5 2,877,040 3/59 Curtiss' et al. 292-2515 2,935,353 5/60 L66b- 292-251 3 2,943,881 7/ 0 Duhm 292- 251;5 3,026,134 3/62 Ahlgren 292-2515 3,050,324 8/62 Faber, 292-251.5 3,078,134 2/63 Haynes 292-2515 X HENSON WOOD,.JR., Primary Examiner. 

1. A MAGNETIC CATCH ADAPTED TO SECURE A DOOR THAT IS PROVIDED WITH A MAGNETICALLY PERMEABLE STRIKE PLATE, SAID CATCH COMPRISING: A HOUSING OF NON-MAGNETIC MATERIAL INCLUDING SIDE AND TOP PLATE MEMBERS COOPERATING TO DEFINE A CHAMBER WITH AN OPENING GENERALLY CONFRONTING SAID DOOR; A MAGNET ASSEMBLY MOUNTED IN SAID CHAMBER AND SPACED FROM OPPOSITE SIDE PLATE MEMBERS OF SAID HOUSING FOR ROTATION THROUGH A SMALL ANGLE THEREIN WHEREBY TO ACCOMMODATE THE RELATIVE POSITIONING OF SAID CATCH AND SAID STRIKE PLATE, SAID MAGNET ASSEMBLY INCLUDING A PERMANENT MAGNET COMPRISING MAGNETIC PARTICLES BONDED TOGETHER BY A RUBBER MATRIX, SAID MAGNET HAVING COUPLING APERTURES OPENING FROM OPPOSITE POLE FACES THEREOF, SAID ASSEMBLY FURTHER INCLUDING A MAGNETICALLY PERMEABLE METAL POLE PIECE DISPOSED IN CONTACT WITH EACH OF SAID FACES AND EXTENDING AN EDGE PORTION THROUGH THE OPENING IN SAID CHAMBER WHEREBY READILY TO ENGAGE SAID STRIKE PLATE, SAID POLE PIECES HAVING INTEGRAL BOSS MEANS DISPOSED INWARDLY FROM THE MARGINS THEREOF AND PRESSED INTO SAID COUPLING APERTURES WITH A PRESS FIT THEREBETWEEN, SAID POLE PIECES BEING POSITIVELY AND MECHANICALLY COUPLED TO SAID MAGNET SUBSTANTIALLY IMMOVABLY LOCKING SAID EDGE PORTIONS IN ALIGNMENT FOR ROTATION IN UNISON INTO FULL MAGNETIC CONTACT WITH SAID STRIKE PLATE; AND STUD MEANS PENETRATING SAID TOP PLATE MEMBER AND SAID MAGNET ASSEMBLY TO RETAIN SAID ASSEMBLY IN SAID CHAMBER AND PROVIDE A PIVOT ABOUT WHICH SAID ASSEMBLY IS ROTATABLE. 